You Do Need power plug adapter while traveling from Eritrea to Canary Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Canary Islands are C, E and F and in Eritrea are C and L. This is how they look like.

Eritrea

In Eritrea, outlets of type C and L are in use.

Type C

Type L

Canary Islands

In Canary Islands, outlets of type C, E and F are in use.

Type C

Type E

Type F