From the microinformation of the "survey on technological innovation 1998-2000" a database is constructed by the manufacturing Spanish companies that realize activities of innovation. Subsequently, by testing Pearson Chi-square and Mann-Whitney, test whether the size of companies influences the participation of innovative manufacturing companies in the systems of public support for innovation as well as the address of that conditioning. In this regard, the contrasts made indicate that the variable size is related to the variable public funding, and which are the larger companies which benefit most from public support for innovation.