In a laser apparatus, transmission of vibration, which is generated in a portion that generates a cooling gas flow, to a laser unit is suppressed, and heat generated from the laser unit is efficiently dissipated. A laser unit is housed inside a box-shaped housing having a plurality of faces. A frame supports a laser unit with a first mount interposed therebetween inside the housing. The frame has a through-hole penetrating from one face side to the other face side. A blower fan generates a flow of cooling gas for cooling the laser unit. The blower fan is attached to, for example, a second housing so as to face the laser unit. The cooling gas moves through the through-hole of the frame between the blower fan and the laser unit.