An orthogonal two-axis moving apparatus is provided with a first guide member extending along a vertical direction, a second guide member mounted on the first guide member for movement along the vertical direction and extending along a horizontal direction, and a slide block mounted on the second guide member for movement along the horizontal direction. A timing belt having its opposite ends fixed to the slide block is passed over first and second drive rollers rotatably mounted on the opposite ends of the first guide member and rotatively driven by first and second motors, four idle rollers rotatably supported on one end of the second guide member and two idle rollers rotatably supported on the other end of the second guide member, and a driven roller rotatably supported on the slide block.