The invention relates to a particle ray irradiation device which aims at eliminating hysteresis lag influences of a scanning electromagnet, and achieving high-accuracy beam irradiation in raster scanning and mixing scanning. The particle ray irradiation device comprises a scanning power source (4) and an irradiation control device (5), the scanning power source (4) outputs an exciting current of the scanning electromagnet (3), the irradiation control device (5) controls the scanning power source (4) and comprises a scanning electromagnet command value learning generator (37), the scanning electromagnet command value learning generator (37) evaluates a pre-scanning result, an command value (Ik) of the exciting current is updated to execute pre-scanning under the condition that the evaluation result does not meet the specific conditions,, the exciting current command value (Ik) with the evaluated result meeting the specific conditions is output to the scanning power source (4), and pre-scanning is a series of irradiation motions based on the command value (Ik) of the exciting current output by the scanning power source (4).