To provide a motor-integrated magnetic bearing device in which the long term durability of rolling bearings for a thrust load can be improved, which is compact and can cope with high-speed rotation, and in which the motor can be highly efficiently cooled by a simple structure.

The rolling bearing and a magnetic bearing support a main shaft 13 on which a rotor 28a of the motor 28, a compressor impeller and a turbine impeller are installed. An electromagnet 17 forming the magnetic bearing is attached to a spindle housing so as to contactlessly oppose a thrust plate 13a provided on the main shaft 13. A motor stator 28b is installed on the spindle housing so as to oppose the motor rotor 28a. A motor cooling path penetrating through a portion where the motor 28 is provided is provided in the spindle housing. A refrigerant passing groove 44 is provided on the electromagnet 17 so as to face the motor cooling flow path. The motor cooling flow path 41 is interposed on a refrigerant flow path of a refrigeration cycle device where a compressor and an expansion turbine are interposed.