Inspired by the geometric mean due to Atteia and Ra\"\i ssouli, we discuss a general theory of convex functional means on a Hilbert space like the Kubo-Ando theory of operator means. Though our construction is based on the integral representation in Kubo-Ando theory, it is an exact extension not only for operator means but also for Atteia-Ra\"\i ssouli's ones. We give an example where our geometric mean can be defined even if their geometric one cannot. We show that our convex functional means satisfy monotonicity, semi-continuity, homogeneity, subadditivity, joint concavity, transformer inequality and normalization. One of outstanding properties of these means appeares in those for constant functions, which suggests us to weights for operator means.