Negative electrode material for nonaqueous secondary battery and nonaqueous secondary battery comprising same negative electrode material

A negative electrode material for a lithium ion nonaqueous secondary battery, comprising a composite metal oxide containing an amorphous structure which comprises tin as a main component and at least one element selected from the group consisting of elements belonging to the groups I, II, XIII, XIV and XV in the periodic table, transition metal elements and halogen elements, at least a part of said composite metal oxide comprising a particle synthesized from a tin-containing compound as a starting material by a sol-gel method, wherein said particle is a secondary spherical particle having an average particle diameter of from 0.1 μm to 50 μm, is an aggregate particle of a primary particle and is a porous particle having a specific surface area by a BET method of not less than 2 m2/g.