  BL Lacertae is the prototype of the blazar subclass known as BL Lac type
objects. BL Lacertae object itself is a low-frequency-peaked BL Lac(LBL). Very
high energy (VHE) gamma ray emission from this source was discovered in 2005 by
MAGIC observatory while the source was at a flaring state. Since then, VHE
gamma rays from this source has been detected several times. However, all of
those times the source was in a high activity state. Former studies suggest
several non-thermal zones emitting in gamma-rays, then gamma-ray flare should
be composed of a convolution. Observing the BL Lacertae object at quiescent
states and active states is the key to disentangle these two components.
VERITAS is monitoring the BL Lacertae object since 2011. The archival data set
includes observations during flaring and quiescent states. This presentation
reports on the preliminary results of the VERITAS observation between January
2013 - December 2015, and simultaneous multiwavelength observations.
