A mask device with blower comprising: an exhaust valve that is provided on an anterior portion of a face body, and moves in an opening direction at the time of exhausting air and in a closing direction at the time of inhaling air; an inhalation valve that is provided on the anterior portion of the face body, and moves in a closing direction at the time of exhausting air and in an opening direction at the time of inhaling air; a blower that is driven by a motor, and supplies external air to an inner portion of the face body through the inhalation valve when the blower operates; and a sensor for blower control (14, 28) that is disposed in the vicinity of the exhaust valve, and detects a movement position of the exhaust valve at the time of inhaling air in a non-contact state with respect to the exhaust valve and generates a signal; wherein, when a person who wears the mask device inhales air, power is supplied to the motor to operate the blower, and when the person exhausts air, power supply to the motor is stopped or reduced, based on the signal that is output from the sensor (14, 28) for blower control (14, 28), the mask device with blower further comprising: a sensor for warning (15, 29) that detects a position of the exhaust valve which is caused to move when an internal pressure of the face body is lower than an outer atmospheric pressure in a non-contact state with respect to the exhaust valve and outputs a signal, at the time of inhaling air; and a control circuit that receives the signal output from the sensor for warning (15, 29) and operates a warning device, wherein each of the sensor for blower control (14, 28) and the sensor for warning (15, 29) is composed of a non-contact sensor that monitors a state of the exhaust valve. an exhaust valve that is provided on an anterior portion of a face body, and moves in an opening direction at the time of exhausting air and in a closing direction at the time of inhaling air; an inhalation valve that is provided on the anterior portion of the face body, and moves in a closing direction at the time of exhausting air and in an opening direction at the time of inhaling air; a blower that is driven by a motor, and supplies external air to an inner portion of the face body through the inhalation valve when the blower operates; and a sensor for blower control (14, 28) that is disposed in the vicinity of the exhaust valve, and detects a movement position of the exhaust valve at the time of inhaling air in a non-contact state with respect to the exhaust valve and generates a signal; wherein, when a person who wears the mask device inhales air, power is supplied to the motor to operate the blower, and when the person exhausts air, power supply to the motor is stopped or reduced, based on the signal that is output from the sensor (14, 28) for blower control (14, 28), the mask device with blower further comprising: a sensor for warning (15, 29) that detects a position of the exhaust valve which is caused to move when an internal pressure of the face body is lower than an outer atmospheric pressure in a non-contact state with respect to the exhaust valve and outputs a signal, at the time of inhaling air; and a control circuit that receives the signal output from the sensor for warning (15, 29) and operates a warning device, wherein each of the sensor for blower control (14, 28) and the sensor for warning (15, 29) is composed of a non-contact sensor that monitors a state of the exhaust valve.