REACTOR

PROBLEM TO BE SOLVED: To provide a reactor capable of improving a heat radiation performance by reducing vibration.SOLUTION: A reactor 1 comprises: a cylindrical coil 2 generating a magnetic flux by energization; a core 3 made of magnetic powder mixture resin formed by mixing resin with magnetic powder, and inside which the coil 2 is embedded; and a columnar central core part 4 arranged in an axial line direction X of the coil 2 on an inner peripheral side of the coil 2, and at least part of which is embedded inside the core 3. Contact faces 401, 402 contacting a stationary member holding and fixing the central core part 4 from both sides in the axial line direction X are formed at both ends of the axial line direction X of the central core part 4. Surface roughness Rz of a contact face 403 of the central core part 4 contacting the core 3 is larger than surface roughness Rz of the contact faces 401, 402. An intermediate face 404 having surface roughness Rz smaller than that of the contact face 403 and larger than that of the contact faces 401, 402 is formed on the central core part 4.