Spark plug for internal combustion engine

A spark plug for an internal combustion engine, comprising:

• a cylindrical housing;
• a cylindrical insulator held inside the housing;
• a center electrode held inside the insulator such that a tip part of the center electrode projects;
• and
• a ground electrode that is connected to the housing and forms a spark discharge gap between the center electrode and the ground electrode, wherein
• the ground electrode includes an erecting part that is erected from a tip part of the housing to a tip side and an inclined part that is bent from the tip of the erecting part to the center electrode side to extend obliquely toward a tip side,
• an end edge of the ground electrode on an opposite side to the housing side is a tip of the inclined part,
• the erecting part satisfies w/t≤1, w≤1.9 mm, and t≤2.3 mm, where t is a dimension in an alignment direction of the erecting part and the center electrode, and w is a dimension in a width direction orthogonal to each of the alignment direction and a plug axial direction, and
• an inclination angle θ of the inclined part with respect to the plug axial direction satisfies 30°≤θ≤60°.