In a multi-polarity type spark plug (1,2) for an internal combustion engine, a tubular insulator (4) is supported within a cylindrical metallic shell (3) through which the spark plug (1,2) is to be attached to an internal combustion engine. A center electrode (5) is placed within the insulator (4), a front end of the center electrode (5) being directed in use toward a combustion chamber of the internal combustion engine from a front end (10) of the metallic shell (3) so as to extend beyond a front end (11a) of the insulator (4). First (6) and second (7) ground electrodes are each connected to the front end (10) of the metallic shell (3), the first ground electrode (6) forming a first spark gap (G1) with a front end surface (12) of the center electrode (5), and the second ground electrode (7) forming a second spark gap (G2) with an elevational side (13) of the center electrode (5). An angle θa is in the range 60° ≦ θa ≦ 150°, where the angle θa is the angle between the first ground electrode (6) and the second ground electrode (7) with the center electrode (5) as an axial center.
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