To solve such a problem of a portable cutting device such as a magnetic drilling machine that a cutting liquid cannot be smoothly supplied to a rotary blade if a tank vent hole is closed with the cutting liquid in making holes on a wall face as the device is used to cut various members at construction sites where an angle of using a body is not only horizontal and also used to make the holes on the wall face in a case of making the holes on piled steel products.

The problem is solved by the cutting device including a motor, the rotary blade driven by the motor, an oil tank for storing cutting oil, and a vent pipe for connecting the inside of the oil tank with the open air. The cutting device is equipped with a mass part on the vent pipe to direct the vent pipe in an antigravity direction.