Panasonic L10 has a 10.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor . You can shoot at maximum resolution of 3648 x 2736 pixels with aspect ratios of 4:3, 3:2 and 16:9. L10 has a native ISO range of 100 - 1600 and it can save files in RAW format which gives you a wider room for post processing.
Panasonic L10 is not the highest resolution Four Thirds camera. Panasonic G95 with its 20.3MP sensor is leading in this class. Check the comparison of Panasonic L10 vs Panasonic G95 or take a look at Highest resolution DSLR cameras list.
Panasonic L10 DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Panasonic L10 sensor has been tested by DxO Mark and got an overall score of 55 for its image quality. You can find the details of their analysis of Panasonic L10 here.
Let's look at how the size of the Panasonic L10's Four Thirds sensor compares with other standard sensor sizes.