Joint member and method for producing joint member

A method for producing a joint member, comprising:

• forming a cubic lattice part on a surface of a base material in a metal member;
• and
• joining a resin member to the metal member by embedding the cubic lattice part with a resin,
• wherein the forming of the cubic lattice part includes forming the cubic lattice part to include a plurality of lattice points and a plurality of arms connecting the lattice points, respectively, as well as forming the cubic lattice part such that, of the plurality of lattice points, an outermost lattice point that is farthest from the surface of the base material includes at least three lattice points forming an inclined surface with respect to the surface of the base material.