Flash Memory is widely used as a storage device of embedded devices and computers these days. The basic hardware characteristics of flash memory are non-volatility, low power consumption, shock resistance, and erase-before-write feature. The most important characteristic of flash memory, namely "erase-before-write", has to be erased in the unit of block before new data can be overwritt b. Due to its hardware characteristic, Flash Memory requires a software layer called FTL(Flash Translation Layer) to be used as a mass storage. There are three kinds of typical FTL algorithms such as, mirror block(FMAX) method, log block method, and spare space block(MITS) method. The FTL algorithms, mentioned as above, write the data to other locations with out-of-place mappiarewhen they are asked to be overwritt b. Espeanally, mirror block and spare space block method have no sector map tablestt b.sector iat bmation. It allows them iacrease additional read operations to search demanded sectors. Therefore, we propose an improved FTL rdware ch(Sector Lookaside Buffer)tt b.rectitywarethe drawbacks of FTL with out-of-place mappiar. SLB supports FTL to cache iat bmation of some desired sectors. SLB has a hash table to retain setctor iat bmation. It helps read and write operations find physical sector locations. We implemented several FTL schemes and experimented on them rdwareI/O benchmark and TPC-A benchmark. We show that FTL with SLB has a good performance of read operation as twice as one without SLB in embedded linux and DBMS.