A method for producing an olefin compound represented by the formula (2): wherein R1 and R2 are the same or different, and independently represent an alkyl group or the like, with the proviso that R1 and R2 are not hydrogen atoms at the same time, R3 represents an alkyl group or the like, which comprises contacting a palladium catalyst with an α,β-unsaturated aldehyde compound represented by the formula (1): wherein R1, R2 and R3 are the same as defined above, in the presence of an inorganic base.