| abstract |
Provided is a catalyst for producing an unsaturated carboxylic acid, in which a ratio of a diffraction line intensity of 2θ=19.1±0.3° with respect to a diffraction line intensity of 2θ=10.7±0.3° in X-ray diffraction measurement is 0.20 or more and less than 0.58, and the catalyst having an active component represented by formula (A) shown below: n Mo 10 V a P b Cu c As d X e O g (A) |