A spark plug including: a rod-shaped center electrode; an insulator; a metal shell; a ground electrode joined to the metal shell and bent toward the center electrode; a noble metal tip joined to an end portion of the ground electrode and opposing a leading end portion of the center electrode via a gap; and a bulge portion. A part of the noble metal tip is embedded in the ground electrode, and another part of the noble metal tip protrudes from a distal end surface of the ground electrode. A relationship A≧0.25 mm is satisfied where A (mm) is a protruding length of the noble metal tip from the distal end surface. The bulge portion covers a center part of a boundary between the noble metal tip and the end surface in a width direction.