A method for diagnosing a tank venting valve. This includes measuring a first pressure p1 in the induction pipe of an internal combustion engine; activating the tank venting valve so as to open; measuring a second pressure p2 in the induction pipe of the internal combustion engine after the opening activation of the tank venting valve; calculating a control value K by subtracting the first induction pipe pressure p1 from a second induction pipe pressure p2 and adding a correction pressure pK, which is calculated from the leakage air adaptation of an internal combustion engine; and detecting A defect of the tank venting valve, when the control value K falls below a threshold value.