You are a posted worker if your employer sends you to another country to work but the insurance contributions related to your wages are still paid in Finland. You must be covered by Finnish social security for the entire period of your employment abroad.
Your membership of IAET-kassa must also remain valid throughout. Because your insurance contributions are paid in Finland, your work abroad is comparable to work in Finland, which is why you must remain a member of an unemployment fund in Finland.
A decision regarding you being covered by Finnish social security must be applied for in advance, before you relocate to the target country. Such a decision will be issued by either the Finnish Centre for Pensions or Kela. Apply to the Finnish Centre for Pensions for a decision when you are going to work in a country with which Finland has a social security treaty (e.g. the EU area, Australia, Chile, Canada and the USA). Kela is where you should apply for a decision when you are going to work in a country with which Finland does not have a social security treaty (e.g. China, Russia). See which countries have a social security treaty with Finland.
If you remain unemployed after an employment relationship, your daily allowance is calculated based on your wages for insurance purposes. Those are the wages regarding which your employer paid statutory insurance contributions in Finland. Your wages for insurance purposes may differ from what you were actually paid abroad; always check the wages that your employer has declared as the basis for your insurance contributions.