Chatter is one of the major barriers for the robotic machining process. As the dominant vibration frequency of the chatter varies under different working conditions, MagnetorheologicaI elastomers (MREs) whose stiffness is adjustable is an ideal device to be used for chatter control. This paper presents a new chatter reduction scheme by attaching an MREs device on the spindle to absorb vibration at a specific frequency range. Firstly, a test was implemented to check the frequency shift property of the designed MREs and then robotic milling of an aluminium block using ABB IRB6660 robot are tested at various conditions. The experimental results showed a notable potential to reduce the chatter/vibration in the robotic milling application through semi-active vibration reduction using MREs device.