To provide a laver harvester effective for preventing the entanglement of a laver culture net with a rotary cutter.

A guide bar 14 is extended in the longitudinal direction of a base 11 to support the laver culture net together with a net traction roller 13. The guide bar 14 is fixable at a position adjustable in horizontal and vertical directions relatively to the base 11 to separate the laver culture net from the rotary cutter 12 by a prescribed distance. A holding bar 15 is extended along the length of the rotary cutter 12 at a position higher than the cutter 12 and is slidable along the circumference of the rotary cutter 12. A net engagement prevention member 16 is extended between the guide bar 14 and the holding bar 15. The net traction roller 13 has guide grooves 29a, 29b, 29c for holding the ropes of the laver culture net and pulling the ropes by the rotation of the roller and a plurality of ridges 30 inclined to guide the rope toward the guide grooves 29a, 29c from inside according to the rotation of the roller.