To provide a resist peel-off device and a method, wherein a proper amount of resist releasing agent is applied to the resist-applied surface of a semiconductor substrate and wastage of resist peel-off agent is eliminated.

A resist peel-off device is equipped with a substrate supporting member 2 which fixes, supports and rotates a semiconductor substrate 1 that is placed on it making the resist-applied surface face upward, a peel-off agent feed means 3 which makes the peel-off agent drip down near the center of the resist-applied surface 1a of the semiconductor substrate 1, a peel-off agent detecting means 4 which detects the spread of peel-off agent supplied onto the resist-applied surface 1a of the semiconductor substrate 1, and a control means 5 which controls the feed of resist peel-off agent, corresponding to the spread of resist peel-off agent detected by the peel-off agent detecting means 4 or controls the number of revolutions of the substrate support member 2.