A blower includes a lower case provided with an inlet; a first tower that extends upward from the lower case and is formed with a first outlet; a second tower that extends upward from the lower case and is provided with a second outlet; a fan that is rotatably disposed on the lower case; a first air flow converter that is disposed at the first tower; and a second air flow converter that is disposed at the second tower, each of the first air flow converter and the second air flow converter including: a guide board that is disposed inside the first tower or the second tower or protrudes through a first wall or a second wall; an upper gear that rotates in engagement with an upper portion of the guide board; a lower gear that rotates in engagement with a lower portion of the guide board; a shaft that is connected to each of the upper gear and the lower gear to rotate together; and a motor that is connected to one of the upper gear and the lower gear to provide a driving force.