To provide a trouble-free mask with blower.

The mask device 1 with a blower is equipped with: an expiration valve 7 which moves toward the opening direction upon expiration while moves toward the closing direction upon inspiration and an inspiration valve 8 which moves toward the closing direction upon expiration while moves toward the opening direction upon inspiration set in front of the mask body 2; and a blower 10 which is driven by a motor 11 and sends external air into the mask body through the inspiration valve 8 during the motor 11 works. The expiration valve is constituted of a material mixed with a magnetic body.