While most rice cookers are made of steel, stainless steel, or ceramic, units with glass parts are also available because if you care about your health, it is important to use a cooker that leaves out plastic entirely. Consider purchasing a rice cooker that comes with a lid made from glass rather than plastic, the usual material of many cooking machines. On websites like http://www.ricecookersportal.org/ you can find information regarding glass rice cookers.
Here are the reasons
Depending on the brand, rice cookers can have a holding capacity of 6 to 20 cups, and feature a steamer for vegetables and fish, a nonstick cooking bowl for uniform cooking, a measuring cup, as well as handles and a tempered glass lid that stays cool. Even though many units cook and shut off automatically, requiring little or no intervention on your part, having a transparent glass lid allows you to see the contents and oversee the cooking process if you so prefer.
Glass over plastic
Glass cookers are very stylish and come in many different colors and finishes that will fit any modern kitchen; the only downside is that, since the glass lid has no vent (as plastic ones do), water may splash out from beneath the glass and make a mess of your countertop. The plastic vent alternative, on the other hand, can let out a lot of steam, which may be a problem if your kitchen has cabinets mounted on the wall, above the countertop. It is therefore up to you to weigh both options and determine which fits better into your kitchen.
Cleaning is easy, especially if you leave the rice cooker to soak for a while; just make sure to unplug it. You can wipe both the lid and the body with a damp cloth, but avoid scrubbing the surface. The measuring cup and any other accessories can be washed with some liquid soap and a sponge.