The critical specific heat capacity c of a d-dimensional model describing structural phase transitions in an anharmonic crystal with a long-range interaction (decreasing at large distances r as r
−d−σ
, 0 < σ ≤ 2) is studied near the classical critical point Tc
. At temperatures T > Tc
and for dimensions σ < d < 2σ (σ and 2σ are the lower and the upper critical dimensions, respectively) the critical specific heat capacity is obtained in the form c ≈ 1 − Dεαs
, where D > 0 and αs
< 0 depend only on the ratio d/σ, and ε = T/Tc
−1 is a measure of the deviation from the critical point. For three fixed values of the ratio d/σ the dependence c ≈ c(ε) is graphically presented. It is shown that at all temperatures T ≤ Tc
the specific heat capacity retains its maximum value, c
max = 1. The critical exponent αs
, obtained here, coincides with that of the known mean spherical model, while c
max is different for the two models.