ELECTROMAGNET

PURPOSE:To provide an electromagnet which can keep the intensity of a magnetic field in a proportional relation with that of a current on a high magnetomotive force side without enlarging an iron core in size. CONSTITUTION:An electromagnet is composed of a pair of magnetic poles 100 possessed of an inter-magnetic pole gap 4 and an air layer gap 5 inside, a coil 3 which is provided in the inter-magnetic pole gap 4 and generates a magnetic field when a current flows through it, and an elastic member 20 which is so provided to a part of the air layer gap 5 as to control the gap 5 in width corresponding to a magnetic force which acts on the gap 5. By this setup, a magnetic material can be restrained from increasing in magnetic resistance on a high magnetomotive force side without enlarging a magnetic pole in area. Therefore, an electromagnet, which can keep the intensity of a magnetic field in a proportional relation with that of a current from a low magnetomotive force side (low coil current) to a high magnetomotive force side (high coil current) without enlarging it in size, can be realized.