The present invention provides a metal thin film type magnetic recording medium including a non-magnetic substrate made from a polyamide film whose surface configuration is controlled so as to obtain an optimal fine configuration of a magnetic layer surface, enabling to simultaneously obtain a preferable electro-magnetic conversion characteristic and preferable running characteristic. The non-magnetic substrate is made from an aromatic polyamide film formed in such a manner that fine protrusions having an average height of 5 to 50 nm are formed in a range of 103 to 105 thousand pieces/mm2 on a surface where a ferromagnetic metal thin film is to be formed.