A point-of-sale system comprising: a cash processing machine having a cash receiving port and a cash dispensing port disposed on a first lateral side thereof; a register machine having a display and an operational panel and coupled with the cash processing machine such that the display and the operational panel face a second lateral side of the cash processing machine that is opposite to the first lateral side; and a receipt printer having a receipt outlet from which a receipt is ejected, the receipt printer being movable between a first position in which the receipt outlet is closer to the first lateral side than the second lateral side and a second position in which the receipt outlet is closer to the second lateral side than the first lateral side; the receipt printer being placed on a top surface of a platform formed in the register machine ; the platform including a main body and a top plate that is attached to the main body and on which the receipt printer is placed; characterized in that the top plate including one or more guides on a first end portion thereof and one or more guides on a second end portion that is opposite to the first end portion, the one or more guides on the first end portion and the one or more guides on the second end portion are spaced apart such that a bottom portion of the receipt printer fits therebetween and a move of the receipt printer in a direction from the first end portion to the second end portion and in a direction from the second end portion to the first end portion is restricted; each of the one or more guides on the first end portion comprises a protrusion that extends upward and has a surface formed along an edge of the top plate in the first end portion; and each of the one or more guides on the second end portion comprises a protrusion that extends upward and has a surface formed along an edge of the top plate in the second end portion. a cash processing machine having a cash receiving port and a cash dispensing port disposed on a first lateral side thereof; a register machine having a display and an operational panel and coupled with the cash processing machine such that the display and the operational panel face a second lateral side of the cash processing machine that is opposite to the first lateral side; and a receipt printer having a receipt outlet from which a receipt is ejected, the receipt printer being movable between a first position in which the receipt outlet is closer to the first lateral side than the second lateral side and a second position in which the receipt outlet is closer to the second lateral side than the first lateral side; the receipt printer being placed on a top surface of a platform formed in the register machine ; the platform including a main body and a top plate that is attached to the main body and on which the receipt printer is placed; the top plate including one or more guides on a first end portion thereof and one or more guides on a second end portion that is opposite to the first end portion, the one or more guides on the first end portion and the one or more guides on the second end portion are spaced apart such that a bottom portion of the receipt printer fits therebetween and a move of the receipt printer in a direction from the first end portion to the second end portion and in a direction from the second end portion to the first end portion is restricted; each of the one or more guides on the first end portion comprises a protrusion that extends upward and has a surface formed along an edge of the top plate in the first end portion; and each of the one or more guides on the second end portion comprises a protrusion that extends upward and has a surface formed along an edge of the top plate in the second end portion. <EOS>