A telescopic crane, includes a substructure, a superstructure rotatably mounted onto the substructure, a counterweight and a telescoping boom structure which includes a main boom slewable about a luffing plane. The main boom has a boom base and at least one telescope section received in the boom base and displaceable between retracted and extended positions. At least one guy support is mounted to the boom structure and connected to a guy rope which extends substantially longitudinally in the direction of the boom structure. The guy support is oriented with respect to the luffing plane at an inclination which is so selected that a lateral load acting on the boom structure is partially or entirely received by the guying.