The objective of this study was to design and study a potato chip dryer using heat transfer oil, the drying chamber as 640 mm x 1,340 mm x 840 mm. The blowing fan was a curve vane the flow rate 0.42 m3/s, 0.37 kW fan motor, 2.41 kW heat exchanger capacity. The fuel pump the flow rate was 0.16 kg/s with 0.19 kW motor power. Infrared gas burner power was 3.45 kW. Product capacity was 10 kg, contained in 10 Trays which each tray can place the potato 1 kg. Initial moisture content was around 600-650%, dry basis. Final moisture content was 10-15%, dry basis. The velocity of air inside the drying chamber was 0.4-0.7 m/s and the proportion of recycled air was 70%. The fuel pump fed high temperature heat transfer oil to heat exchanger. The fan blew outside air into the heat exchanger to get hot air passed through drying chamber which reduced the moisture content of the potato chips. The experimental results showed that at temperature 50, 60 and 70oC, The drying time was 4.5, 4.0 and 3.5 hr, the average drying rate was 1.88, 2.12 and 2.42 kg/hr, the average specific energy consumption was 15.85, 15.88 and 16.89 MJ/kg. Therefore, concluded that drying a potato chip at proper is the temperature 70oC.