An integrated environmental sustaining apparatus for maintaining a terrarium is adapted to simultaneously regulate temperature and deliver water droplets. The apparatus includes three major systems a thermoelectric device, a water droplet delivery system, and a thermostat. The thermoelectric device is used to release heat or absorb heat. The water droplet delivery system includes a water pump, a water pipe and at least one water droplet dispersing device connected to the water pipe. A section of the water pipe is coupled to the thermoelectric device such that water flowing inside the water pipe will thermally communicate with the thermoelectric device. The thermostat is used to power on or off the thermoelectric device and the water pump in response to the temperature measurement inside the terrarium in relation to a predetermined temperature range determined by a low-temperature setting and a high temperature setting that can be programmed into the thermostat.
