The 33-year-old, who spent last season at Chelsea, has scored four goals, two of which came in last weekend's 3-1 victory over Burnley, since his loan move to Goodison Park in the summer.
"The qualities Eto'o brings to the team are those of the highest, highest calibre of player," Martinez said in this morning's press conference.
"Eto'o feels excited and really stimulated to show everyone what he can do. He's enjoying his football and he does it in style. [He] comes in every day with really high standards, he always wants to do more and he is a big influence in that way."
On Saturday, Everton will face Martinez's former club Swansea City on Merseyside.