PURPOSE: To provide a special effect device which ensures a visual and smooth wiping effect of an optional speed by performing the wiping border control of the minimum pixel unit or less.

CONSTITUTION: A special effect device contains a border coefficient generating means 70 which calculates a fraction of the minimum pixel unit of a wiping border position less than one pixel and one line based on the field count value showing the process of fields and the set value of shift extent per field and outputs this fraction as a 1st border coefficient α (0<α<1) and (1-α) as a 2nd border coefficient respectively. Then a 1st multiplication means 30 is added to calculates (1st image data ×-α) based on the 1st image data and the 1st border coefficient α together with a 2nd multiplication means 40 which calculates (2nd image data × (1-α)) based on the 2nd image data and the 2nd border coefficient (1-α), and a means 50 which adds together the outputs of the means 30 and 40 with the timing corresponding to the wiping border position of a displayed image.