A construction machine comprising an undercarriage designed as a running gear and an upper carriage with a housing having side walls, wherein for access to the housing at least one housing opening with an access wall is provided, which is adjustable into an open position, and in an area in front of the housing opening a horizontal gangway is formed. At least one pull-out element is provided which can be pulled out horizontally between a retracted position and a pulled out position, in which the pull-out element projects horizontally from the housing, and in order to form the gangway a base plate is provided on the pull-out element.