Alkyl, (CH₃)₃COC(CH₃)₂CH₂, and alkyl peroxy, (CH₃)₃COC(CH₃)₂CH₂O₂, radicals from di-tert-butyl ether (DTBE), have been studied in the gas phase at 296 K. A pulse radiolysis UV absorption technique was used to measure the spectra and kinetics. Absorption cross sections were quantified over the wavelength range 220-330 nm. At 240 nm, σ_{(CH3)3COC(CH3)2CH2} = (3.6 ± 0.4) × 10^-18 cm² molecule^-1 and at 260 nm, σ_{(CH3)3COC(CH3)2CH2O2} = (3.8 ± 0.3) × 10^-18 cm² molecule^-1 have been obtained. The observed rate constants for the self-reaction of (CH₃)₃COC(CH₃)₂CH₂ and (CH₃)₃COC(CH₃)₂CH₂O₂ radicals were found to be (2.9 ± 0.2) × 10^-11 cm³ molecule^-1 s^-1 and (2.7 ± 0.2) × 10^-12 cm³ molecule^-1 s^-1, respectively. For the reaction of the alkyl radical with O₂ in 1 atm pressure of SF₆ a rate constant of (7.2 ± 1.1) × 10^-13 cm³ molecule^-1 s^-1 was found. The rate constants for the reaction of the alkyl peroxy radicals with NO and NO₂ were determined to be (1.8 ± 0.2) × 10^-12 and (9.9 ± 1.3) × 10^-12 cm³ molecule^-1 s^-1, respectively. As a part of the work the rate constants k(F + DTBE) and k(O + DTBE) were determined to be (2.6 ± 0.6) × 10^-10 and (4.0 ± 0.9) × 10^-12 cm³ molecule^-1 s^-1, respectively.