A printer with an improved ribbon guide mechanism. A pair of ribbon guides is mounted via fixing members, one being on each of both sides of a printing head, so as to be positioned in the path of a print ribbon. Thus the ribbon guides are movable together with the printing head to an operating position and a rest position. Leaf springs are provided to press the ribbon at all times against the ribbon guides on either side of the printing head. This allows the length of a portion of the print ribbon moving through between the guides on either side of the printing head to be maintained substantially constant, whether the printing head is at its operating position or at its rest position, thereby preventing the occurrence of slackness in the ribbon.