  Motivated by the drying pattern experiment by Yamazaki and Mizuguchi[J. Phys.
Soc. Jpn. {\bf 69} (2000) 2387], we propose the dynamics of sweeping interface,
in which material distributed over a region is swept by a moving interface. A
model based on a phase field is constructed and results of numerical
simulations are presented for one and two dimensions. Relevance of the present
model to the drying experiment is discussed.
