| abstract |
A process for producing methacrolein and methacrylic acid by catalytically oxidizing isobutylene or tertiary butanol in the presence of a catalyst comprising a compound oxide containing molybdenum, bismuth and iron as the essential components, wherein a catalytic oxidation reaction is started at a temperature of (T-3)° C. or lower wherein T° C. is defined as the boundary temperature of activation energy of a reaction for obtaining methacrolein and methacrylic acid from isobutylene using said catalyst, the reaction is continued while the reaction temperature is increased as the activity of the catalyst decreases, and an activation treatment is conducted for the catalyst at least once before the reaction temperature exceeds the boundary temperature of activation energy. |