Joined solid production method

A method for producing a joined solid, the method comprising:

• placing a metal powder on a solid;
• covering at least a portion of the periphery of the metal powder with a high-melting-point material having a melting point higher than the melting point of the metal powder;
• and
• irradiating the metal powder, at least a portion of the periphery of which is covered with the high-melting-point material, with microwaves to heat the metal powder, thereby sintering or melt-solidifying the metal powder to form a metal solid on the solid,
• wherein in the portion of the metal powder covered with the high-melting-point material, the metal powder and the high-melting-point material are in close contact with each other, and
• the high-melting-point material includes a mixture of:
• an insulation material that has a lower degree of absorption of the microwaves than the metal powder, and
• an absorbent material that absorbs the microwaves in a temperature zone at least a portion of which is lower than a temperature zone in which the metal powder absorbs the microwaves.