An integrated optical memory with a long storage lifetime based on a waveguide fabricated in a rare-earth-ion-doped crystal is developed in this work by utilizing femtosecond-laser-micromachining. This optical memory features a cross-section with 20 μm diameter and an insertion loss of 5 dB. A demonstration of long-life optical storage in the memory shows that the storage efficiency decay of the memory exhibits a multi-exponential pattern, with characteristic time constants of 4.9 ± 0.1 h and 14.2 ± 0.8 h. This optical memory has a storage efficiency of 8.1% at a storage time of 1.4 s, and a storage efficiency of 0.6% is achieved at maximum storage time of 24 hours. Such long-lived crystal waveguide based memory is potential to be extended to a 2-dimensional integration array, and is expected to be applied in integrated optical information processing.