1. A motor drive unit mounted on a cabinet, comprising:an electronic component; and
a housing surrounding the electronic component, and including:
a back plate which is fixed to the cabinet and to which the electronic component is fixed;
a front plate opposite the back plate; and
a first side plate and a second side plate which extend from the back plate to the front plate so as to be opposite to each other, wherein
the first side plate includes an opening extending through the first side plate, the first side plate is slanted with respect to the back plate so as to approach the second side plate or separate from the second side plate the further from the back surface plate toward the front surface plate wherein the motor drive unit is mounted on the cabinet in close proximity to an other member the other member also having a side plate, wherein the first side plate faces and directly contacts the side plate of the other member and is slanted so as to form a gap between the first side plate and the side plate of the other member to allow an air flow through the opening and the gap to be generated.