To provide a wall surface air conditioner with favorable workability, only a little pressure loss of a passage, no air clogging or the like, and favorable operation efficiency and heat exchange efficiency.

The wall surface air conditioner has a supply side main pipe 18 and a return side main pipe 20 adjacently arranged substantially in parallel with each other, and passing heat exchange fluid, and a pipe unit 14 comprised of a plurality of slim heat exchange pipes 22 with both ends connected between each main pipe 18, 20, extending in a perpendicular direction with respect to each main pipe 18, 20, doubled back at a certain length, and communicating each main pipe 18, 20 with each other. A cross-sectional area of an inner diameter of each main pipe 18, 20 is larger than a summation of cross-sectional areas of inner diameters of the heat exchange pipes 22. A holding plate 12 is provided for holding each main pipe 18, 20 and the heat exchange pipe 22 and to be used as a backing material, and the holding plate 12 has a holding groove 17 for holding the heat exchange pipe 22.