Provided is a thermal activation device capable of preventing a heat-sensitive
adhesive sheet from being partially excessively heated, keeping a
short distance between a contact between a
thermal head and a platen roller, and a
discharge port, and preventing a structure of the thermal activation device from being complicated and a size thereof from increasing. While a heat-sensitive
adhesive sheet (2) is transported along a transport path (15) through rotations of
insertion rollers (3) and a platen roller (5), a heat-generating portion (4a) of the
thermal head (4) is caused to generate heat, thereby thermally activating a heat-sensitive
adhesive layer of the heat-sensitive adhesive sheet (2). When a
trailing edge of the heat-sensitive adhesive sheet (2) reaches a position where the
trailing edge thereof is not in contact with the platen roller (5), a transporting force is not transmitted to the heat-sensitive adhesive sheet (2), thereby stopping transportation thereof. At that time, an
adhesion prevention member (6) is allowed to enter the transport path (15) to lift and hold the
trailing edge of the heat-sensitive adhesive sheet (2) to a position where the trailing edge thereof is not in contact with the
thermal head (4).