In the beta decay :

${}_Z{}^{A}X\to {}_{Z+1}{}^{A}Y + e^{-}$

In beta decay neutron decays to proton 

${}_0{}^{1}n \to p^{+} + e^{-}$+ antineutrino

spin of $p^{+}, e^{-} \text{and} {}_0{}^{1}n$ is $\frac{1}{2}$ and spin of antineutrino is $-\frac{1}{2}$

Therefore, spin (RHS) is either $\frac{1}{2}$

spin (LHS) is $\frac{1}{2}$.

spin (RHS) = spin (LHS) 

Hence, spin angular momentum is  conserved.

Total energy, mass number & charge is conserved as can be seen by equation.