An airflow-direction adjustment device, comprising: a case set in such a way as to blow out air to an outside from a front-side opening portion; a plurality of fins wherein upper and lower ends are pivotally supported turnably relative to opposed support portions inside the case; a link mechanism associating two or more of the fins; and an operating knob so as to adjustably switch between a parallel air-blowing mode wherein the fins become substantially parallel to each other, and a scattered air-blowing mode wherein two or more of the fins (16C, 16E) are turned in a direction opposite to each other through the knob, wherein the knob is supported movably to front and back and right and left in a state connected to an intermediate fin disposed in a middle among the plurality of fins, and the link mechanism includes two first links (14B, 14C), each turnably connecting at one end to one first fin (16C, 16E) disposed adjacent to the intermediate fin, and turnably connecting at another end to the intermediate fin, characterized in that the knob is connected or linked to the intermediate fin through a piece portion of the intermediate fin and due to a forward movement of the intermediate fin, the piece portion and the front side enter into a relief opening located in an intermediate portion of the right and left of a horizontal-type fin supporting the knob and located downstream the vertical-type fins to be released by maintaining a state approximately parallel to rackets (17A, 17B) mounted on an inside face of the right and left of the case and the horizontal-type fin being supported by the brackets (17A, 17B). a case set in such a way as to blow out air to an outside from a front-side opening portion; a plurality of fins wherein upper and lower ends are pivotally supported turnably relative to opposed support portions inside the case; a link mechanism associating two or more of the fins; and an operating knob so as to adjustably switch between a parallel air-blowing mode wherein the fins become substantially parallel to each other, and a scattered air-blowing mode wherein two or more of the fins (16C, 16E) are turned in a direction opposite to each other through the knob, wherein the knob is supported movably to front and back and right and left in a state connected to an intermediate fin disposed in a middle among the plurality of fins, and the link mechanism includes two first links (14B, 14C), each turnably connecting at one end to one first fin (16C, 16E) disposed adjacent to the intermediate fin, and turnably connecting at another end to the intermediate fin, characterized in that the knob is connected or linked to the intermediate fin through a piece portion of the intermediate fin and due to a forward movement of the intermediate fin, the piece portion and the front side enter into a relief opening located in an intermediate portion of the right and left of a horizontal-type fin supporting the knob and located downstream the vertical-type fins to be released by maintaining a state approximately parallel to rackets (17A, 17B) mounted on an inside face of the right and left of the case and the horizontal-type fin being supported by the brackets (17A, 17B).