Manufacturing device and method of catalyst for producing methacrylic acid wherein the device includes a compressor, a dehumidifier, a heater and a steam generator

The present invention provides a catalyst for producing methacrylic acid with a stable catalyst activity in all seasons. A roasting device 10 of the present invention includes: a compressor 12 that sucks external air in and compresses it; a dehumidifier 13 that is connected to the compressor 12 through a first pipe 11a and dehumidifies the external air compressed by the compressor 12; a heater 14 that is connected to the dehumidifier 13 through a second pipe 11b and heats the external air dehumidified by the dehumidifier 13; a roasting furnace 15 that is connected to the heater 14 through a third pipe 11c, is supplied with the external air heated by the heater 14 and bakes a precursor of a catalyst containing heteropoly acid compounds containing phosphorus and molybdenum for producing methacrylic acid with the external air heated by the heater 14; and a steam generator 16 that is connected to any one of the second pipe 11b or the third pipe 11c or both through fourth pipes 11da and 11db which supply steam to