A magnetic bearing device, comprising: a magnetic bearing that supports a rotor shaft in a state of non-contact, using an electromagnetic force of an electromagnet (3, 5, 7); and a controller that controls the magnetic bearing, wherein the controller includes: a current acquisition means (32, 33) for acquiring current detection values (lp, lm) flowing in a pair of the electromagnets that attract the rotor shaft of the magnetic bearing in opposite directions or a current instruction value (Cxhp, Cxhm); a correction coefficient arithmetic means for determining, from said current detection values or the current instruction value, a correction gain instruction value (Kcomp) of a pair of the electromagnets, which results from a mounting posture of the magnetic bearing; a first addition means for adding up the correction gain instruction value and a fundamental gain (Kctrl), which is uniquely determined irrespective of the mounting posture of the magnetic bearing, to obtain a gain instruction value; and a current control means (38, 40, 41, 31) for controlling respective currents flowing in a pair of the electromagnets, using the current instruction value (Cxhp, Cxhm) generated on the basis of the gain instruction value, wherein the gain instruction value of the electromagnet in direction of gravity changes depending on the mounting posture. a magnetic bearing that supports a rotor shaft in a state of non-contact, using an electromagnetic force of an electromagnet (3, 5, 7); and a controller that controls the magnetic bearing, wherein the controller includes: a current acquisition means (32, 33) for acquiring current detection values (lp, lm) flowing in a pair of the electromagnets that attract the rotor shaft of the magnetic bearing in opposite directions or a current instruction value (Cxhp, Cxhm); a correction coefficient arithmetic means for determining, from said current detection values or the current instruction value, a correction gain instruction value (Kcomp) of a pair of the electromagnets, which results from a mounting posture of the magnetic bearing; a first addition means for adding up the correction gain instruction value and a fundamental gain (Kctrl), which is uniquely determined irrespective of the mounting posture of the magnetic bearing, to obtain a gain instruction value; and a current control means (38, 40, 41, 31) for controlling respective currents flowing in a pair of the electromagnets, using the current instruction value (Cxhp, Cxhm) generated on the basis of the gain instruction value, a current acquisition means (32, 33) for acquiring current detection values (lp, lm) flowing in a pair of the electromagnets that attract the rotor shaft of the magnetic bearing in opposite directions or a current instruction value (Cxhp, Cxhm); a correction coefficient arithmetic means for determining, from said current detection values or the current instruction value, a correction gain instruction value (Kcomp) of a pair of the electromagnets, which results from a mounting posture of the magnetic bearing; a first addition means for adding up the correction gain instruction value and a fundamental gain (Kctrl), which is uniquely determined irrespective of the mounting posture of the magnetic bearing, to obtain a gain instruction value; and a current control means (38, 40, 41, 31) for controlling respective currents flowing in a pair of the electromagnets, using the current instruction value (Cxhp, Cxhm) generated on the basis of the gain instruction value, wherein the gain instruction value of the electromagnet in direction of gravity changes depending on the mounting posture.