The invention relates to the land clearing device for use in conjunction with a hydraulic boom crane. The land clearing device comprises a body (2) which can be connected to the head of the hydraulic boom crane (1), a hydraulic motor (3,4), supported on the body, and a blade (5), operated by the hydraulic motor. In accordance with the invention, two elongated blade guides (6) are supported on the body (2), with two blade panels (7), reciprocating at the same pace and in opposite directions, supported between said blade guides, which blade panels are connected to the hydraulic motor (3,4) and both comprise knife-like blade rows (8), extending flush with each other in opposite directions.