The methoxymethyl radical, CH3OCH2,, is prepared via hydrogen photodissociation from dimethyl ether during codeposition of CH3OCH3 in excess argon at 4 K with laser-excited metal plume radiation. The spectrum of this radical is characterized by four infrared absorptions at 1468.1, 1253.9, 12266, and 944.4 cm(-1), which are assigned by deuterium substitution as well as frequency and intensity calculations using density functional theory. The O-CH2 bond length is calculated to be 0.07 A shorter than the CH3-O bond due to additional pi bonding interactions. In the matrix near-UV irradiation destroys the CH3OCH2 radical with the formation of HCO radical and CH4, which is different from the decomposition mechanism of CH3OCH2 radical to H2CO and CH3 radical proposed for the gas phase process.