The present invention relates to a sorter (1) and a method for sorting wood pieces and for guiding them to a conveyor means (4). This type of sorter comprises a lower frame (2), a receiving deck (6) for wood pieces, and a feeder (7) for detaching a wood piece from the receiving deck. Said feeder comprises control means (8) for supporting the wood piece (5, 51, 52) during movement directed to it and transferring it substantially vertically from the receiving deck. In that case the control means is traversed by at least two bearers (10) controlled by an actuator (11) for producing the vertical movement of the wood piece. The bearers are arranged to project from an outer surface of the control means (8) by an amount of projection that is adjustable during lifting. The feeder (7) further comprises measuring means (12) for detecting a wood piece of the largest cross-sectional diameter on the bearers and for controlling the projection of the bearers to a position corresponding to this diameter.