To provide a pellet stove and its operation control method preventing falling of a pellet in an unburned state, and capable of effectively dumping ash.

The pellet stove is characterized by an ash dump device 32 arranged in a lower opening 36B of a combustion box 30 having a combustion space 36 opened at the top and bottom. The ash dump device has a cylindrical rotor 58 capable of rotating around a horizontal rotation axis 52, and a plurality of plates 60 fixed to the rotor so as to extend in a radial direction of the rotor. The operation control method of the pellet stove has an operation start step, a normal operation step repeatedly carried out thereafter, and an operation stop step. In the normal operation step, action of operating a pellet feeder 26 for a predetermined time at predetermined time intervals is repeated a predetermined number of times, and then the ash dump device is operated for a predetermined time. In the operation stop step, the ash dump device is operated for a predetermined time.