To acquire continuous observation results is an essential demand to environmental monitoring. Wireless sensor networks (WSNs), composed of many tiny sensing equipment, give a good solution to collect continuously temporal and spatial data. Due to the limitation of WSNs, such as volume of wireless sensors, cost, energy, processing capability, and transmission distance, we need a solution in charge of collecting sensed data and transmitting it to the backend server. This solution has to handle all data in the network, so the stability and processing capability are a top priority. As a solution, we purpose a gateway with energy-efficiency embedded system that supplies a suitable interface and solve the problem of limited energy source. We employ a touch screen with external devices to provide users the gateway status to deal with the unpredictable situations. We design a power supply set comprising a lead-acid battery and a solar cell. Under adequate exposure to the sun, it can supply sufficient energy for long-term monitoring.