In microbiology, an incubator is a device for controlling the temperature, humidity, and other conditions in which a microbiological culture is being grown. The simplest incubators are insulated boxes with an adjustable heater, typically going up to 60-65°C (140-149°F), though some can go slightly higher (generally to no more than 100°C). More elaborate incubators can also include the ability to lower the temperature (via refrigeration), or the ability to control humidity or CO₂ levels.

Most incubators include a timer; some can also be programmed to cycle through different temperatures, humidity levels, etc. Incubators can vary in size from tabletop to units the size of small rooms.