  We performed inelastic neutron scattering experiments on single crystal
samples of a linear magnetoelectric material Mn$_{3}$Ta$_{2}$O$_{8}$, which
exhibits a collinear antiferromagnetic order, to reveal the spin dynamics.
Numerous modes observed in the neutron spectra were reasonably reproduced by
linear spin-wave theory on the basis of the spin Hamiltonian including eight
Heisenberg interactions and an easy-plane type single-ion anisotropy. The
presence of strong frustration was found in the identified spin Hamiltonian.
