Diaphragm pump, comprising: a pump chamber (26; 56) comprising an inlet opening and an outlet opening; a passive silicon check valve at the inlet opening; a passive silicon check valve at the outlet opening; a metallic pump diaphragm (14; 54) that adjoins the pump chamber (26; 56); and an actuating means (16, 24) for moving the pump diaphragm (14; 54) from a first end position, which defines a first pump chamber volume, to a second end position, which defines a second pump chamber volume, a difference between the first pump chamber volume and the second pump chamber volume defining a stroke volume, wherein the pump chamber (26; 56) comprises a pump chamber floor, which is opposite the metallic pump diaphragm (14; 54), the pump chamber floor being adapted to the maximum deflection of the pump diaphragm (14; 54), a gap remaining between the pump chamber floor and the pump diaphragm (14; 54) when the pump diaphragm is in the end position, which defines a smaller pump chamber volume than the other end position, which gap offers, for a flow through same, a flow resistance no larger than a flow resistance of the passive check valve at the outlet opening or than a flow resistance of the passive check vale at the inlet opening, and wherein the check valves (32, 34) comprise a valve flap (32a, 34a) and a support ridge (32b, 34b) on which the valve flap (32a, 34a) rests when the check valve (32, 34) is closed, said support ridge having a width of ≤ 50 μm, ≤ 20 μm, ≤ 10 μm, or ≤ 5 μm, characterized in that the gap that remains between the pump chamber floor and the pump diaphragm when the pump diaphragm is in the end position that defines a smaller pump chamber volume than the other end position is larger in the central area of the pump chamber than in an edge area of same. a pump chamber (26; 56) comprising an inlet opening and an outlet opening; a passive silicon check valve at the inlet opening; a passive silicon check valve at the outlet opening; a metallic pump diaphragm (14; 54) that adjoins the pump chamber (26; 56); and an actuating means (16, 24) for moving the pump diaphragm (14; 54) from a first end position, which defines a first pump chamber volume, to a second end position, which defines a second pump chamber volume, a difference between the first pump chamber volume and the second pump chamber volume defining a stroke volume, wherein the pump chamber (26; 56) comprises a pump chamber floor, which is opposite the metallic pump diaphragm (14; 54), the pump chamber floor being adapted to the maximum deflection of the pump diaphragm (14; 54), a gap remaining between the pump chamber floor and the pump diaphragm (14; 54) when the pump diaphragm is in the end position, which defines a smaller pump chamber volume than the other end position, which gap offers, for a flow through same, a flow resistance no larger than a flow resistance of the passive check valve at the outlet opening or than a flow resistance of the passive check vale at the inlet opening, and wherein the check valves (32, 34) comprise a valve flap (32a, 34a) and a support ridge (32b, 34b) on which the valve flap (32a, 34a) rests when the check valve (32, 34) is closed, said support ridge having a width of ≤ 50 μm, ≤ 20 μm, ≤ 10 μm, or ≤ 5 μm, characterized in that the gap that remains between the pump chamber floor and the pump diaphragm when the pump diaphragm is in the end position that defines a smaller pump chamber volume than the other end position is larger in the central area of the pump chamber than in an edge area of same.