A method for damping vibration in a forest machine, in which a desired driving speed is maintained and reduced driving speed is automatically maintained when a wheel (17) of the forest machine is descending from the top of an obstacle (23) rising from the ground or to a recess in the ground. The forest machine comprises a drive transmission with several wheels (17), a control system (18) arranged to maintain the desired driving speed of the forest machine and to control the drive transmission, wherein the control system (18) is also arranged to automatically maintain the reduced driving speed when a wheel (17) of the forest machine is decending from the top of an obstacle (23) rising from the ground or to a recess in the ground. A forest machine comprising a sensor (22,24,25) coupled to the forest machine and arranged to observe the profile of the ground on the travel path of the wheel (17) of the forest machine.
