Heating device and method of manufacturing magnetic recording medium

A heating device for heating a workpiece having a disk shape with a hole in a center and having a pair of main surfaces opposite to each other by irradiating the workpiece with light, the heating device comprising:

• an irradiating part facing at least one main surface of a pair of main surfaces of a workpiece and configured to irradiate the workpiece with light,
• wherein the irradiating part includes a plurality of light emitting elements on a surface thereof facing the at least one main surface of the workpiece,
• the surface of the irradiating part facing the workpiece includes a first region including a position corresponding to a center of the workpiece, a second region surrounding the first region from an outer side, and a third region surrounding the second region from an outer side and including a position corresponding to an outer periphery of the workpiece, and
• an amount of light emission per unit area in the third region is greater than an amount of light emission per unit area in the first region and an amount of light emission per unit area in the second region,
• wherein an outer periphery of the first region, an outer periphery of the second region, an outer periphery of the third region, the outer periphery of the workpiece, and a shape of a hole of the workpiece are concentric circles when viewed in a direction perpendicular to the main surfaces of the workpiece,
• in a case where a radius of the workpiece is defined as RW and a radius of the hole is defined as RH, a radius of the outer periphery of the first region is 0.50RH or more and 0.43RH+0.57RW or less, and a radius of the outer periphery of the second region is 0.40RH+0.60RW or more and 0.03RH+0.97RW or less, and
• L1/L2 is 0.70 or less, and L2/L3 is 0.050 or more and 0.80 or less, where L1 is the amount of light emission per unit area in the first region, L2 is the amount of light emission per unit area in the second region, and L3 is the amount of light emission per unit area in the third region.