Antero Manninen (born January 19, 1973), also known as Mr. Cool, is a session musician and former band member of Finnish Cello metal quartet Apocalyptica. He was an official member but did not write the music and left in 1999 due to prior commitments, although he has come back to help the band several years ago.
Manninen seated, calm composure playing style is at stark contrast with the headbanging antics of the others when playing live. Besides his job in Apocalyptica he used to work as a musician in a Tapiola Sinfonietta Avanti! and Finnish Radio Symphony Orchestra and in the orchestra of the Finnish National Opera. He is also one of the founders of Sibelius-Academy’s Cellosextet (SSS). Antero has been performing also at funerals. Currently he is a member of the Lahti Symphony Orchestra.