In recent years, the magnetic recording storage industry has developed a growing interest in increasing recording density of the magnetic disks. Since dimensions of the recording head read transducer have been scaled down to increase areal density, all other parameters being equal, the energy required to cause damage by an ElectroStatic Discharge (ESD) event is reduced substantially. The present work characterizes the thermal transport properties of Al2O3 gap layer, which are essential to address the ESD failure. This study provides data for out-of-plane thermal conductivity of thin Al2O3 layers, which are obtained using steady-state Joule heating and electrical-resistance thermometry technique. © 2005 Elsevier Ltd. All rights reserved.