A door actuating device, including a housing, at least one drive unit which is disposed in the housing and can be coupled to a door leaf, and at least one spring energy accumulator, which is in operative connection with the drive unit, and which includes a spring disposed therein under spring pretension, wherein the spring pretension of the spring is realized by means of a spring adjusting device, which includes at least one screwed sealing plug, which can be connected to the housing, and an adjusting nut, where a cylinder is configured at the screwed sealing plug and oriented towards the spring, at which cylinder the adjusting nut is linearly guided, where a setting element which is guided by means of the screwed sealing plug and, at least in sections, can be brought non-positively and positively into engagement with the cylinder, and which bears against the adjusting nut, serves for adjusting the spring pretension.