A jaw crusher, a mineral material processing plant and a method for processing mineral material. The jaw crusher includes a fixed jaw and a movable jaw for forming a crushing chamber therebetween which is open at the top. The fixed jaw includes a first wear part mounted thereto and the movable jaw includes a pitman and a second wear part mounted thereto. The pitman is rotatably mounted to a first eccentric shaft. The pitman is further rotatably mounted to second eccentric shaft configured to guide the stroke of the movable jaw to create a movement pattern with a substantially linear crushing stroke, wherein the eccentricity of the second eccentric shaft is larger than that of the first eccentric shaft.