A compact mid-wavelength infrared zoom camera with a zoom range of 20:1 and automatic athermalization has been developed. The moving groups for a wide zoom range are only two lens groups and the loci of zoom are very simple, which allows easy access of optomechanical and electromechanical design. In addition, the microscanning technique was introduced to improve resolving power. We acquired increased resolving power of 7.6 cycles/mrad, superior to the original Ny- quist frequency of 4.5 cycles/mrad. The temperature range, being -30 to + 55°C, in which the camera is to operate, is rather wide. The minimum resolvable temperature difference of the zoom camera is 0.3°C at 6 cycles/mrad.