An allyl-containing resin is provided. The allyl-containing resin comprises a repeating unit comprising a structural unit represented by the following formula (I): wherein, R1 to R3 in formula (I) are as defined in the specification; the Fourier transform infrared spectrum of the allyl-containing resin has a signal intensity “a” from 1650 cm−1 to 1630 cm−1 and a signal intensity “b” from 1620 cm−1 to 1560 cm−1, and 0