The design and construction of an inexpensive temperature programmer for use with a Carle Model 311 isothermal gas chromatograph is described. The operator may control the initial and final temperatures and the rate of temperature increase between these limits. Initial and final temperatures between ambient and 399°C may be chosen with programmed temperature rates between 00.0 and 39.9°C/min in increments of 0.1°C. Most temperature programmers are restricted to programming rates which increase in powers of two. This programmer is readily adaptable to other gas chromatographs or any instrument which incorporates a thumbwheel-switch, incremental voltage divider for control.