Franciscan Father K. König was the first who came with idea to establish the castle museum in 1941. He established the first Castle Commitee as well. The Commitee began to gather money to set up the institution and an entreaty was sent to the Hungarian National Museum in Budapest to make an archeological research of the area. The research started in 1944 under the conductorship of dr. János Kalmár. The world war stopped the process of establishing the museum and the research itself too.
The first regional museum of the „Slovak part“ of Novohrad region was established in 1951. It was called The County Museum of National History and Geography in Fiľakovo. In 1960 it was transformated into the City Museum. The County Museum of National History and Geography in Lučenec moved to Fiľakovo in 1967. It´s seat was in Halič castle from the year 1955. From 1967 to 1984 there were two constant expositions: the exposition of the Town Museum - on the ground floor of the Franciscan monastery and the exposition of the Novohrad Museum - in Vigado. In 1984 the Novohrad Museum moved to Lučenec because of the bad conditions and in 1988 the exposition in the monastery was closed down too.
In 1993 a new era in the history of Fiľakovo museum has begun. The Ministry of Culture of the Slovak Republic accepted the requests of the town. Part of the collection was donated to the town Fiľakovo. The reconstructed Town Museum became the department of the Town Cultural Centre and a constant exposition was opened in 1994 in three rooms of Vigado. After 15 years there was a need to reorganize the institution.
Another idea of establishing the Castle Museum came again in 2005. Between 2006 - 2007 there was a reconstruction of the interior of the Bebek Bastion and it´s adaptation into the museum. In April 2007 the Castle Museum in Fiľakovo was established. In August 2008 a constant exposition called The Centuries of Fiľakovo castle was opened in the museum. Visitors can learn about the history of the town and the castle from the first written reference to 1682 when the castle was destroyed. There are exhibited valuable medieval finds and finds from the Slovak National Museum, the original castle keys and things from the Turkish occupation. On the ground floor there are valuable finds from the most important archeological localities.
The Town Museum of National History and Geography works in a new institution. It´s exposition was closed in summer 2008. The building is going to be reconstructed and the new exposition will be about the history of Fiľakovo after the destruction of the castle. The Castle Museum organizes short exhibitions in the so called Gallery of the Town Museum and on the other two floors of the Bebek Bastion.