The present disclosure refers to a cylinder head (1) of a static spark-ignited gas engine. The cylinder head may comprise at least two exhaust ports (7.1, 7.1') and at least two inlet ports (1.1, 1. 1') which run to a bottom side (1.3) of the cylinder head (1). The cylinder head (1) have at least one cylinder axis (9) and each inlet port (1.1, 1. 1') may have a valve seat (2, 2') for inlet valves. Each of said valve seats (2, 2') may have a center axis (2.1, 2. 1'), with at least one inlet port (1.1, 1. 1') having a countersink (3, 3') in the border area of the bottom side (1.3) of the cylinder head (1). The countersink (3, 3') may have an offset axis (3.1, 3.1') shifted from said center axis (2.1, 2. 1') effecting a swirl flow. A radius RF, RF' of said countersink (3, 3') may have a point M, M', said point M, M' being a radial maximum with reference to the center axis (2.1, 2. 1'). The radius RF, RF' and a straight line MG, MG' may include an angle φ. The straight line MG, MG' may connect the cylinder axis (9) with the center axis (2.1, 2. 1') of said valve seat (2, 2') of said inlet port (1.1, 1. 1'). The angle φ may fulfill the following condition: 70°