An apparatus for detecting whether an image signal is in a film mode, includes a first field buffer, a second field buffer and a third field buffer that sequentially buffer respective fields of the image signal by order of input, using the respective fields stored in the first, the second and the third field buffers. The apparatus for detecting whether an image signal is in the film mode, includes a motion information calculator calculating a motion information of the respective fields by comparing variations of a motion in the respective fields stored in the first and the third field buffers, a motion information buffer storing the motion information in unit of a predetermined number of fields, and a pattern matching unit determining whether the image signal is in the film mode by comparing the motion information of the respective fields stored in the unit of the predetermined number of fields with a pattern of the field having a predetermined periodicity in accordance with a 3:2 pull-down conversion, and by subsequently determining whether the motion information matches the pattern.